THE LP-MOVPE OF GAINAS WITH SATURATED GROUP-III PRECURSORS

This contribution presents the results of growth kinetic studies using trimethylindium-diisopropylamine-adduct ((CH3)3InNHi(C3H7)2 (TMIAd)) as an indium precursor and dimethylaminopropyl-galla-cyclohexan (CCH2)5Ga(CH2)3N(CH3)2 (APGH)) as Ga source for the LP-MOVPE (low pressure metalorganic vapour phase epitaxy) of GaInAs/InP. For comparison, experiments using the standard sources trimethylindium ((CH3)3In (TMI)) and trimethylgallium ((CH3)3Ga (TMG)) were also carried out. It is shown that GaAs and InP layers with properties comparable to that grown with the standard sources can be grown with these saturated Ga and In compounds. In the case of GaInAs/InP, the dependence of the solid composition on the variation of the V/III ratio demonstrates that the use of the coordinatively saturated group III precursors leads to a reduction of undesired prereactions between the group III compounds and AsH3. This is in contrast to the standard group III sources. In order to achieve lattice-matched growth, quite different Ga/In ratios are necessary because of the different diffusion constants of the group III precursors. The electrical data of the GaInAs/InP layers grown with both saturated or standard group III sources do not show significant differences. This fact, together with the improved growth process, indicates the advantages of the novel group III precursors.